Yeah, your definition is in line with EA's. I thought their blog about 3-4 man tackles last year was hilarious. Problem is, EA seems to have a MAX of 2, and even that's rare. In Madden, no matter what, if a 3rd defender comes in, someone is taken out. The game seems to have a max of 3 models interacting. And even that's rare.
9 times out of 10, only the 1st defender engages. At best, a 2nd defender may come clean up, knocking the 1st tackler off. In '08, I may have seen 1-2 2-man tackles(2 defenders engaged at the same time) per game. And understand why folks don't like this, especially with all this new control over ball carriers and the talk of broken tackles. The key to bringing down a back is gang tackling. If we can't get more than 1 defender to wrap the ball carrier up, RBs will be running wild.
Watch a Cheifs, Browns, Vikings, Cowboys, Giants, 49ers game... teams with stronger RBs, and see how often it takes 2+ defenders to take them down. It happens quite often.